To calculate the average price of Dave’s position as of the end of day on Tuesday, we need to consider the total value of his position and the total quantity of shares he owns.

Total value of Dave’s position = Value of KNIGHT shares = $275,000

Total quantity of shares Dave owns = Quantity of KNIGHT shares = 22,000 shares

Average price of Dave’s position = Total value of position / Total quantity of shares = $275,000 / 22,000 shares = $12.50 per share

Therefore, the average price of Dave’s position as of the end of day on Tuesday is $12.50 per share.

To calculate Dave’s total return as of the end of day on Tuesday, we need to consider the change in value of his position and any cash flows.

Change in value of Dave’s position = Value of KNIGHT shares at the end of Tuesday - Value of KNIGHT shares at the beginning of Monday = $275,000 - $150,000 = $125,000

Total return = Change in value of position / Initial investment = $125,000 / $150,000 = 83.33%

Therefore, Dave’s total return as of the end of day on Tuesday is 83.33%.

If Dave had not borrowed on margin, his return would have been calculated based on his initial investment only.

Total return without borrowing on margin = Change in value of position / Initial investment without margin = $125,000 / $150,000 = 83.33%

Therefore, Dave’s return would have been the same, 83.33%, even if he had not borrowed on margin.